LS1 Gen 3 Pre Ignition

[Cino Buccheri]

Hi Gino From Australia I have an LS1 in my VY Commodore SS, since i have done the following modification to my engine with the following
CAM upgrade
PART NUMBER: CT2871 49938B/49919A-112 DESCRIPTION: HOLD/CHEV LS1 GEN III HYD ROLLER CAM
VALVE SETTINGS: INTAKE 0.000 HOT 0.000 HOT
LIFT: INTAKE @ CAM .344″ @ VALVE .585″ ROCKER RATIO = 1.7
EXHAUST @ CAM .341″ @ VALVE .580″
CAM TIMING OPENS CLOSES ADV DURATION
AT .006″ INTAKE 25 ° BTDC 69 ° ABDC 274 °
TAPPET LIFT EXHAUST 71 ° BBDC 24 ° ATDC 275 °
DURATION @.050″ CENTRE LINE LIFT at T.D.C
IN 222° IN 110° IN .054″ LOBE SEPERATION ANGLE = 112°
EX 224° EX 114° EX
1 3/4″ headers into 2″ exhaust
241 stock aluminum heads saved 30 thou
I have a pre ignition mainly during the summer months when the engine reaches operating temperature between 1500 & 2000 RPM under load.
I have swapped out the thermostat to a lower temperature opening thermostat, I have swapped out spark plugs to Brisk spark plugs and i have had timing taken out which is annoying as it has also reduced rwk.
Any and all suggestions would be greatly appreciated
Regards
Gino

Topic

[Richard Kirshy]

Common causes:
Glowing hot or melted spark plugs
Glowing hot exhaust valve
Burning carbon embers

Generally the fix(s) for pre ignition :
Run higher octane fuel.
Run the engine on the rich side.
Try playing with ignition timing.

[Author]

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